CLINICAL NUCLEAR MEDICINE Volume 25, Number 11, pp 882– 887 © 2000, Lippincott Williams & Wilkins Whole-Body FDG Positron Emission Tomographic Imaging for Staging Esophageal Cancer Comparison with Computed Tomography CAROLYN CIDIS MELTZER, M.D.,*† JAMES D. LUKETICH, M.D.,‡ DAVID FRIEDMAN, B.S.,‡ MARTIN CHARRON, M.D.,* DIANE STROLLO, M.D.,* MANDY MEEHAN, B.S.,‡ GRACE K. URSO, M.A.,‡ MARSHA A. DACHILLE, C.N.M.T.,* AND DAVID W. TOWNSEND, PH.D.* Purpose: The aim of the authors in this study was to critically evaluate the role of whole-body positron emis- sion tomographic (PET) imaging with fluorine-18 fluoro- deoxyglucose (FDG) in staging esophageal cancer, and further to compare this method with conventional imag- ing with computed tomography (CT). Materials and Methods: The authors performed inde- pendent, blinded retrospective evaluations of FDG PET images obtained in 47 patients referred for the initial staging of esophageal cancer before minimally invasive surgical staging. Twenty PET studies from patients with nonesophageal thoracic cancers were randomly se- lected for inclusion in the PET readings. In a subset of 37 of 47 cases, the PET findings were compared with inde- pendent readings of CT studies acquired within the same 6-week interval. The utility of the imaging findings was evaluated using a high-sensitivity interpretation (i.e., assigning equivocal findings as positive) and a low- sensitivity interpretation (i.e., assigning equivocal find- ings as negative). Results: PET was less sensitive (41% in high-sensitiv- ity mode, 35% in low-sensitivity mode) than CT (63% to 87%) for diagnosing tumor involvement in locoregional lymph nodes, which was identified by surgical assess- ment in 72% of patients. Notable, however, was the greater specificity of PET-determined nodal sites (to ap- proximately 90%) compared with CT (14% to 43%). In detecting histologically proved distant metastases (n  10), PET performed considerably better when applied in the high-sensitivity mode, with a sensitivity rate of ap- proximately 70% and a specificity rate of more than 90% in the total group and in the subset of patients with correlative CT data. In the low-sensitivity mode, CT iden- tified only two of seven metastatic sites, whereas the high-sensitivity mode resulted in an unacceptably high rate of false-positive readings (positive predictive value, 29%). PET correctly identified one additional site of me- tastasis that was not detected by CT. Conclusions: The relatively low sensitivity of PET for identifying locoregional lesions precludes its replace- ment of conventional CT staging. However, the primary advantage of PET imaging is its superior specificity for tumor detection and improved diagnostic value for dis- tant metastatic sites, features that may substantially af- fect patient management decisions. In conclusion, PET imaging is useful in the initial staging of esophageal cancer and provides additional and complementary in- formation to that obtained by CT imaging. Key Words: Computed Tomography, Emission To- mography, Esophageal Cancer. F LUORINE-18 FLUORODEOXYGLUCOSE (FDG) has been used extensively to assess glucose metabolism in tu- mors with positron emission tomography (PET) and has been shown to be a useful means to distinguish benign and malignant lesions, to evaluate the extent of local disease, and to detect distant metastases in several types of cancer (for a review, see Conti et al. [1]). Recent reports have supported a role for PET in the evaluation of patients with esophageal cancer (2– 8). We previously published our initial clinical experience with PET and esophageal cancer in 35 consecutive patients (3). In this study, PET detected occult distant disease in 14% of patients. The preliminary experience of others has also suggested that PET imaging, when added to conven- tional imaging techniques, could eliminate invasive sur- gical staging in select cases (4,6). In the current retrospective study, we report our ex- panded experience with PET imaging in esophageal can- cer and compare its performance with the results of surgical staging techniques. The value of PET in this setting was also evaluated by comparing the relative Received for publication February 21, 2000. Accepted June 13, 2000. Reprint requests: Carolyn Cidis Meltzer, M.D., University of Pittsburgh Medical Center, PET Facility, B-938, 200 Lothrop Street, Pittsburgh, Pennsylvania 15213-2582. E-mail: meltzer@radserv.arad.upmc.edu From the Departments of Radiology* and Psychiatry,† and the Section of Thoracic Surgery, Department of Surgery,‡ University of Pittsburgh, Pittsburgh, Pennsylvania 882